AMPA receptor is dynamically regulated in developing synapses and through activity-dependent synaptic plasticity. Our recent studies indicate that the AMPAR is targeted to the synapse by stargazin through two distinct mechanisms. The interaction between stargazin and AMPARs is essential for the surface delivery of the AMPARs, whereas the binding between stargazin and synaptic PDZ proteins mediates AMPAR localization to synapse. The proposed experiments are to investigate the cellular and molecular mechanisms of stargazin-dependent receptor trafficking by understanding the nature of AMPAR-stargazin interaction. This work will have broad implications on molecular mechanisms of synapse formation and plasticity.